1. Field of the Invention
The present invention relates to an information distribution system capable of presenting a contract content, etc., of information to be distributed from a distribution center apparatus on a side of a user terminal apparatus, and its distribution center apparatus and user terminal apparatus, and an information storage medium usable for the system.
2. Description of the Related Art
In recent years, services to distribute electronic data in the use of a communication line have become popular with the spread of broadband. Some of them have started to provide services only through a specific information storage medium for which a contract between a user and a distributor is made. In such services, to prevent duplicating of distribution information, a method, which encrypts the distribution information by using proper information, such as a medium ID written into a read only area in the information storage medium, has been employed.
One of the method provides a service to distribute a video content in use of the information storage medium corresponding to content protection for recordable media (CPRM) in the field of a video distribution service (refer to, for example, JP-A 2004-350150 (KOKAI) and JP-A 2005-159752 (KOKAI)).
In distributing the video content, the service encrypts it with a prescribed key and encrypts to distribute a key for decrypting, with a medium ID of the storage medium, the video content distributed in a view request. Therefore, the user who does not have a medium with its ID cannot decrypt the key. Thereby, the method can surely prevent illegal use of duplicate and has an advantage excellent in copyright protection, even if the video content has been duplicated without permission, because the information storage medium corresponding to the CPRM having the medium ID used for encrypting the key is required to obtain the key to decrypt the encryption. The system regarding the method being capable of downloading the video content to store it in a storage medium, it may select any one of the storage medium of a purchase type capable of viewing indefinitely or a rental type capable of viewing within a given period of time like a commercially available DVD package.
Meanwhile, when viewing the video content associated with the information storage medium by using a communication line, the information distribution system given above presents identification information for a video content and management information, such as a view time period, possible to view through the information storage medium in response to a request from a user. As to a method of the presentation, for instance, storing the management information in an inner memory of a user terminal apparatus, or the information storage medium itself to read and display the management information from a storage area when the information storage medium is set, or to access to a distribution center to acquire and display the management information included in user information managed on the side of the distribution center is a generic approach.
However, in such a presentation method, an increase in the number of media to be used poses the need of replacement and setting of each medium for the user terminal apparatus and it results in troublesome work for the user. Therefore, to identify the management information, the user has to make a print or a handwritten note on the user's own terms.
In distributing information content from the distribution center apparatus, the aforementioned system transmits transmission information of matters for attention and limitations or the like to the user terminal apparatus to present it to the user in the use of a display function on the side of the user terminal apparatus. Therefore, to confirm the transmission information for the distribution of the video content, troublesome processing is required for the user terminal apparatus to set the information storage medium to access to the distribution center apparatus, and for the distribution center apparatus to acquire the necessary transmission information from user information managed on the side of the center apparatus.